PIC12F509-E/MC - 8-bit Flash MCU, 4MHz, 1.5KB | Microchip
MPN: PIC12F509-E/MC ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.85 | $0.85 |
| 10 | $0.78 | $7.80 |
| 100 | $0.66 | $66.00 |
| 500 | $0.58 | $290.00 |
| 1,000 | $0.5 | $500.00 |
PIC12F509-E/MC Overview
What is an 8-bit Flash Microcontroller (MCU)? An 8-bit Flash MCU is a single-chip computer built around an 8-bit data path with non-volatile Flash program memory. The PIC12F509 family uses Microchip's RISC architecture with 33 single-word single-cycle instructions, providing typically 2:1 code compression over competitive 8-bit MCUs and execution times that are 4x faster per instruction than legacy CISC designs.
Key features include six general-purpose I/O pins, an internal 4 MHz RC oscillator, 12-bit-wide instruction words, a wide operating voltage range of 2.0V to 5.5V, and on-chip in-circuit serial programming (ICSP) that allows the device to be programmed after PCB assembly. The PIC12F509 also includes a hardware 8-bit timer with watchdog, power-on reset, brown-out detect, and code protection. With only 8 pins total, it is among the smallest packaged PIC microcontrollers available and is a strong fit for cost- and space-constrained applications.
Architecture depth: the PIC12F509 uses a Harvard bus architecture with separate program and data paths, plus a 2-stage pipeline that overlaps fetch and execute to deliver 1 MIPS performance at 4 MHz. The 12-bit instruction word delivers richer opcode space than 8-bit CISC alternatives and produces more compact code, allowing 1.5 KB of Flash to deliver functionality that often requires 2-3 KB on competing cores. Brown-out detect and a configurable watchdog timer enable robust unattended operation.
Typical applications include low-cost consumer appliances, battery-powered remote sensors, LED lighting controllers, simple fan/thermostat controls, and automotive body electronics (e.g., seat heater controllers, lighting blinkers). The wide 2-5.5V supply range also makes it well suited to single-cell lithium or 2xAA battery products.
When designing with this device, remember that the DFN exposed pad MUST be soldered to the PCB ground plane for thermal and electrical performance. For prototyping, the same silicon is also offered in 8-pin PDIP and 8-pin SOIC packages, which are easier to breadboard.
Drop-in alternatives for PIC12F509-E/MC — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC12F509-E/MC (same form factor and footprint) — differing in Package, Watchdog Timer, Internal Oscillator, Timers, Instruction Set.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12F508-E/MC
✅ Drop-In✓ In Stock
$0.55 / Unit
View Datasheet →PIC12F508-I/MC
✅ Drop-In✓ In Stock
$0.47 / Unit
View Datasheet →PIC12F509-I/MC
✅ Drop-In✓ In Stock
$0.55 / Unit
View Datasheet →PIC12F509T-I/MC
✅ Drop-In✓ In Stock
$0.28 / Unit
View Datasheet →PIC12F509T-E/MC
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C508A-04E/MF
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12F1501-E/MF
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC12F1571-E/MF
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC12F509-E/MC Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC |
| Instruction Set | 33 single-word/single-cycle instructions (12-bit wide) |
| Program Memory (Flash) | 1.5 KB (1K x 12) |
| RAM | 41 bytes |
| Data EEPROM | Not present |
| Max CPU Speed | 4 MHz |
| Operating Voltage | 2.0 V to 5.5 V |
| Operating Temperature | -40C to +125C (Extended, -E suffix) |
| I/O Pins | 6 |
| Timers | 1 x 8-bit (with watchdog) |
| ADC | None |
| Internal Oscillator | 4 MHz RC |
| Watchdog Timer | Yes |
| Brown-out Detect | Yes |
| In-Circuit Serial Programming (ICSP) | Yes |
| Package | 8-pin DFN (2x3 mm) with Exposed Pad |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant (lead-free) |
| Code Protection | Yes (programmable) |
PIC12F509-E/MC Pin Configuration
| Pin 1 | GP5/OSC1/CLKIN — General-purpose I/O / oscillator input / external clock input |
| Pin 2 | GP4/OSC2/CLKOUT — General-purpose I/O / oscillator output / clock output |
| Pin 3 | GP3/MCLR/VPP — General-purpose I/O (input only) / Master Clear reset / programming voltage |
| Pin 4 | VDD — Positive supply voltage (2.0V to 5.5V) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | GP0/ICSPDAT — General-purpose I/O / ICSP data |
| Pin 7 | GP1/ICSPCLK — General-purpose I/O / ICSP clock |
| Pin 8 | GP2/T0CKI — General-purpose I/O / Timer 0 clock input |
| Pin EP | EPAD — Exposed thermal pad - must be soldered to PCB ground for thermal and electrical performance |
Typical Applications
PIC12F509-E/MC is suitable for 6 applications: Battery-Powered Remote Sensor Node, LED Lighting Controller / Blink Pattern Generator, Automotive Body Electronics (Seat Heater, RKE), Low-Cost Consumer Appliance Control, Fan Speed / Thermostat Controller, IR Remote Control Transmitter.
Battery-Powered Remote Sensor Node
The PIC12F509-E/MC fits battery-powered sensor nodes because it draws microamp-level sleep current from its 2.0-5.5V supply and operates directly from a single Li-ion or 2xAA cell without a voltage regulator. With 1.5 KB Flash, the MCU handles periodic wakeup, ADC sampling from external sensor, threshold detection, and low-duty-cycle RF/IR transmission. The internal 4 MHz oscillator eliminates the crystal and its quiescent draw, while the integrated watchdog and brown-out detect guard against firmware lockup and undervoltage Flash corruption in unattended deployments. Compared to a discrete logic replacement, the PIC12F509 delivers configurable firmware upgradeability in the same 8-DFN footprint.
Recommended
LED Lighting Controller / Blink Pattern Generator
The PIC12F509-E/MC is well matched to LED blinker and chasing-light controllers because its 8-bit timer with watchdog can synthesize PWM-like patterns in firmware while the 6 GPIO pins drive up to six discrete LEDs or charlieplexed LED arrays. At 1 MIPS per MHz, the 4 MHz core updates LED state machines faster than the eye can resolve, and the 1.5 KB Flash holds multi-pattern tables. Operating from 2-5.5V allows direct drive from Li-ion or USB rails. The -E extended -40C to +125C temperature grade supports outdoor signage and under-hood automotive lighting.
Recommended
Automotive Body Electronics (Seat Heater, RKE)
For automotive body modules such as seat heater controllers, RKE receivers, and simple lighting blinker ECUs, the PIC12F509-E/MC's -40C to +125C Extended temperature range and 2.0-5.5V supply tolerance cover 12V battery transients when paired with a TVS and LDO. The 1.5 KB Flash is sufficient for state-machine firmware driving FETs via GPIO, while the hardware watchdog detects firmware lockup - a critical safety function. The 8-DFN (2x3 mm) footprint is small enough to embed inside the wiring harness connector, saving PCB area and cost.
Recommended
Low-Cost Consumer Appliance Control
The PIC12F509-E/MC is a strong fit for cost-sensitive consumer appliances (toasters, fans, coffee makers, simple thermostats) where BOM cost is critical. At roughly $0.50 in 1k quantities, the MCU replaces dozens of cents worth of 555 timers, flip-flops, and discrete logic while adding configurability and timing precision. The 1.5 KB Flash stores simple lookup tables for temperature curves or timer sequences, and the integrated watchdog keeps the appliance safe if firmware hangs. Six GPIO pins drive relays, triacs, buttons, and status LEDs without needing a port expander.
Recommended
Fan Speed / Thermostat Controller
Thermostat and fan-speed controllers benefit from the PIC12F509-E/MC's 8-bit timer, integrated watchdog, and ability to read a thermistor voltage divider via comparator-style bit-banging on GPIO. The MCU's 4 MHz core closes a 100 ms PID loop fast enough for thermal regulation of small enclosures, and its 2.0V minimum supply allows direct operation from a single-cell Li-ion or 2xAA backup battery. The 1.5 KB Flash stores hysteresis tables and ramp profiles, while the -E temperature grade ensures reliable operation near the heat source.
Recommended
IR Remote Control Transmitter
The PIC12F509-E/MC is widely used in single-button or multi-button IR remote controls because its 4 MHz core can synthesize 38 kHz / 56 kHz carrier frequencies via timer interrupt for NEC, RC-5, or Sony protocols. Six GPIO pins accept up to six user buttons, with software debouncing and matrix key handling possible within the 1.5 KB Flash budget. The MCU's 2.0V minimum supply lets it run from a single CR2032 coin cell with a low-dropout regulator. The -E temperature grade supports outdoor or automotive garage-door remotes.
Recommended
Recommended Products Summary
Engineering reference data for PIC12F509-E/MC — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12F508-E/MC | PIC12F509-I/MC | PIC12F509T-E/MC | PIC12C508A-04E/MF | PIC12F1571-E/MF |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-DFN (2x3 mm) | 8-DFN (2x3 mm) - same | 8-DFN (2x3 mm) - same | 8-DFN (2x3 mm) - same | 8-DFN (2x3 mm) - same | 8-DFN (2x3 mm) - same |
| Flash Program Memory | 1.5 KB (1K x 12) | 0.75 KB (-50%) | 1.5 KB - same | 1.5 KB - same | 0.75 KB OTP (-50%) | 1.75 KB (+17%) |
| RAM | 41 bytes | 41 bytes - same | 41 bytes - same | 41 bytes - same | 25 bytes (-39%) | 128 bytes (+212%) |
| Max CPU Speed | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz - same | 4 MHz - same | 16 MHz (+300%) |
| Operating Temperature | -40C to +125C (Extended) | -40C to +125C - same | -40C to +85C (Industrial) | -40C to +125C - same | -40C to +125C - same | -40C to +125C - same |
| ADC | None | None - same | None - same | None - same | None - same | 10-bit ADC (superset) |
| Operating Voltage | 2.0V to 5.5V | 2.0V to 5.5V - same | 2.0V to 5.5V - same | 2.0V to 5.5V - same | 2.5V to 5.5V (higher min) | 1.8V to 5.5V (lower min) |
| I/O Pins | 6 | 6 - same | 6 - same | 6 - same | 6 - same | 6 - same |
| Unit Price (qty-1, as of 2026-09-15) | $0.85 | ~$0.75 (lower, smaller Flash) | ~$0.85 - same | ~$0.85 (T&R variant) | ~$0.90 (older OTP) | ~$1.10 (newer, ADC) |
Key Differentiators
- Extended -40C to +125C temperature grade for harsh environments (vs PIC12F509-I/MC)
- Smallest 8-pin package option in the PIC12F509 family (vs PIC12F509-I/P (PDIP-8))
- Larger Flash than the PIC12F508 for slightly more complex firmware (vs PIC12F508-E/MC)
- Pin-compatible upgrade path to newer PIC12F1xxx family (vs PIC12F508-E/MC)
Design Notes
The PIC12F509-E/MC's 8-pin DFN package has a center exposed thermal pad (EPAD) that MUST be soldered to a PCB ground plane for both thermal dissipation and electrical reference. Recommended land pattern: 0.6 mm x 1.5 mm pads on 0.65 mm pitch plus a 1.0 mm x 2.0 mm EPAD with at least 5 thermal vias (0.2 mm diameter) tying it to the inner ground plane. Insufficient EPAD soldering can lead to intermittent failures or thermal shutdown at elevated ambient temperatures.
Place a 100 nF decoupling capacitor as close as possible to the VDD pin (pin 4) using short traces to the VSS plane. For applications with switching loads (relays, LEDs, FETs), add a bulk 1-10 uF capacitor on the same rail. According to the Microchip datasheet, VDD rise time must be monotonic on power-up; if it is not, the internal Power-on Reset may misbehave and the MCLR pin should be driven with an external RC network.
Pin 3 (GP3/MCLR/VPP) is INPUT ONLY when used as GPIO - the datasheet forbids driving it as an output. The MCLR function is enabled by configuration fuse; if disabled, pin 3 becomes a digital input. ICSP programming requires GP0 (ICSPDAT) and GP1 (ICSPCLK) to be accessible on the PCB - do not place series resistors > 4.7 kohm on these pins or in-circuit programming will fail. Brown-out Detect should always be enabled for field-deployed products to protect Flash integrity during voltage dips.
Keep the ICSP pins (GP0/GP1) routed so the programming header can be accessed without removing surrounding components. For automotive or industrial designs, add a TVS diode on VDD and a series ferrite bead to suppress conducted EMI from downstream loads. The internal 4 MHz RC oscillator has a factory calibration of +/- 2% typical - if tighter timing is needed, calibrate in firmware using a known external reference such as the line frequency.
The PIC12F509's GPIO drive strength is rated at 25 mA source/sink per pin, 125 mA total. For capacitive loads > 50 pF, add a series resistor (100-470 ohm) near the driver pin to slow the edge and reduce ground bounce. When the MCU shares a ground plane with high-current switching loads (relays, motors), use a star-ground topology or split ground plane tied at a single point near the MCU's VSS pin to prevent digital noise from coupling into analog signals.
Compliance Information
Lead-free 8-DFN package per DigiKey product listing. Microchip PIC12F509 family is industrial/automotive-under-hood qualified (-E grade) but is not specifically AEC-Q100 documented. Halogen-free status not explicitly stated in provided sources - set to unknown.
